DMSO is used as solvent for HNMR. Reaction of thymol and 4,5-dichlorophthalonitrile was held in DMF, after reaction completed it is precipitated in cold water. TLC and IR spectrum of product were clean. I attached the spectrum file.
Rovshen,
Looking at your provided spectra, it matches very well to that reported in the literature (S. Atalay et al., Acta Cryst., 2004, 60, 303-305, see spetra for cpd 1) with the exception of the peak at 8.5. This peak matches the spectra expected for the dichlorophthalonitrile starting material (for confirmation, see ref: F. Matemadombo, J. Porphyrins Phthalocyanines 2005, 9, 484-490. Look at spectra for cpd 2). I have attached the two references which contain the spectra for both your product and starting material. It looks like you have a 1:1 mixture of them. The provided reference recrystallizes the product from methanol to give pure green crystals. Hope this helps. Good Luck!
If you are referring to the big peak around 3.3 ppm, that would be a water peak. water shows up at 3.3 when DMSO is used as a solvent. The water comes either from poorly dried sample, or old solvents that collected some humidity from the atmosphere.
You can find a compilation of common trace impurities in NMR solvents in the following paper. I used this very often. The data is fully relyable.
For the 3.3 ppm signal I agree with Amjad.
Impurities means they can be already in the solvent, they might have been incorporated into the NMR solvents by careless lab mates, they were attaching to your NMR tube after cleaning or might have been part of your sample.
Hello Rovshen, I assume you are referring to the signals in aromatic region, there is one singlet too much. Could this be impurity of chloroform (8.32 ppm in DMSO-d6)?
Also see published data for the reference:
Article C—H⋯π interactions in 4,5-bis(2-isopropyl-5-methylphenoxy)...
In my opinion the signals at 6.8 ppm, 3.3, 2.9, 2.5 and 1.1 (the small one) do not correspond to the compound.
Which solvent did you use? I cannot find a signal which might correspond to the common solvents such as CDCl3, benzene, acetone, dmso ...
This is important, since the residual signal of these solvents is the reference for the shifts and if this is wrong, all shifts are wrong.
Also, the data in the Gottlieb Nudelman paper are referenced to the common solvents.
E.g. if the signal at 8.32 is really chloroform, your shifts are terribly wrong. CHCl3 has to be at 7.26 ppm.
Thanks all of you guys. You have been very helpful. Especially Mr. Axel Klein thank you for your referenced paper.
Rovshen,
Looking at your provided spectra, it matches very well to that reported in the literature (S. Atalay et al., Acta Cryst., 2004, 60, 303-305, see spetra for cpd 1) with the exception of the peak at 8.5. This peak matches the spectra expected for the dichlorophthalonitrile starting material (for confirmation, see ref: F. Matemadombo, J. Porphyrins Phthalocyanines 2005, 9, 484-490. Look at spectra for cpd 2). I have attached the two references which contain the spectra for both your product and starting material. It looks like you have a 1:1 mixture of them. The provided reference recrystallizes the product from methanol to give pure green crystals. Hope this helps. Good Luck!
Mr. William M. Hewitt thank you for your help. My starting ligand for phthalocyanine is same with the compound at article you send. Its great
Mr. Atajanov, Dr. Hewitt gave you a correct answer. Based on the integral values shown on your spectrum, I calculate a product to 4,5-dichloro-phthalonitrile starting material mole ratio of 1.03 to 1.04. The unresolved multiplets at ca. 2.8-2.9 ppm are from residual DMF solvent; their integral, 2.11, and the integral of the aromatic protons of the starting material, 1.94, are purely coincidental.
Best of luck in your research! AF
P.S. Please recommend Dr. Hewitt's answer. Recommendation is a quick and easy way to thank someone for a high-quality, helpful answer.
Rovshen
You should be careful for the purification of the disubstitue phthalonitriles. When you finished the reaction, sometimes you can obtain 2 different products( chloro-phenol substitue and diphenol substitue) and also may be starting compund. So these side products or impurities may effect the phthalocyanine reactions.( much more different pcs or different isomers etc)
In the H-NMR spectra, about the 8.5 ppm is related with the starting compound(4,5-dichlorophthalonitrile). You said that TLC was clean but i think not clean. I suggest you should change the solvent or solvent mixture for TLC. Other peaks is provided your compounds structure in the H-NMR spectra.
Good luck for your reactions
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